The Future of War - Underground

Although trenches were used in the American Revolutionary War and the U.S. Civil War, World War I is commonly known as the first large-scale trench war. Although trenches offered some protection to troops on both sides from automatic weapons and artillery, World War I was still a bloodbath.

Does this mean an end to tunneling as a major strategic concept?

Unlikely.

For decades, a number of U.S. adversaries have tied their military and strategic future to digging deep. China, North Korea, Iran, Russia, Hamas, and Hezbollah, in particular, have excavated thousands of miles of tunnels, equipping them with military manufacturing plants, airfields, and underground living, training, and strategic missile storage facilities. They have created cities under the earth that are difficult to detect and complicated to destroy.

The Israelis, having infiltrated, explored, and destroyed hundreds of miles of Hamas tunnels, probably have a good idea of what Iranian and North Korean innovations Hamas has incorporated. One assumes that Israel has shared its tunneling insights with U.S. Army engineers.

Some well-publicized tunneling activity dates back to WWII, including the construction of Churchill’s underground bunker in London. Many countries have been prolific diggers. Nazi Germany put many of its aircraft and munitions manufacturing facilities underground. Earlier in his career, the author attended a U.S. Army Intelligence school in Bavaria, adjacent to a subsurface Nazi aircraft manufacturing facility. Russia also digs tunnels. It has, for example, a dedicated, deep emergency-evacuation subway system in Moscow reserved for the strategic use of its elite political and military leaders.

The United States has not relied as much on military/strategic tunneling, but, in the future, the U.S. and its European and Asian allies may have to look down to protect their weapons and facilities from the all-seeing drones and satellites.

To plan for the future, the U.S. and allied governments must fund ongoing research to develop much more efficient and economical tunneling machines and construction techniques. We may also need to create specialized military and civilian units with the expertise to dig in the most cost-effective manner. The 2026 cancellation of the proposed New York/New Jersey Gateway train tunnel under the Hudson River, partly due to high costs, is a striking example of the need to improve the economics of tunneling.

Although the U.S. has a variety of classified detection methods, including satellites, American and allied intelligence almost certainly need more sophisticated remote detection hardware and software to locate and analyze our adversaries' underground networks. AI advances may help improve detection. Sophisticated foreign agents, on or underground, will also be required.

The United States, however, is not without innovative assets.

As Elon Musk dominates the space launch business, his relatively obscure Boring Company (TBC), which provides innovative tunneling solutions, may play a significant role in future underground initiatives. The Germans and the Swiss have also manufactured highly efficient tunneling machines,

One long-term benefit of improved U.S. tunneling experience may be realized when the U.S. begins colonizing the Moon and Mars. To survive on both celestial bodies, astronauts and long-term settlers will almost certainly need to dig residential tunnels to avoid deadly solar radiation and survive underground.

For the present, while drones have us looking up, we must not forget to look down as well.

James S. Fay is a semi-retired lawyer and university administrator. He served as a U.S. Army intelligence officer.

image: U.S. Army Sgt. Michael Lezama, a military police officer assigned to the 615th Military Police Company, 709th Military Police Battalion, 18th Military Police Brigade, pulls rear security for his team in a tunnel system at the Urban Operations Mount Site on U.S. Army Garrison Bavaria, Germany, Aug. 19, 2025. The training helps Soldiers maintain proficiency in tactics and readiness for missions. (U.S. Army photo by Sgt. 1st Class Tanisha Karn)